// common/flags.rs

/// 消息标志位，使用裸 u8 + const 掩码实现
pub const FLAG_NONE:         u8 = 0b00000000;
pub const FLAG_IS_LAST:      u8 = 0b00000001;
pub const FLAG_IS_COMPRESSED:u8 = 0b00000010;
pub const FLAG_IS_HEARTBEAT: u8 = 0b00000100;
pub const FLAG_IS_ERROR:     u8 = 0b00001000;
// 预留高四位供将来扩展
